Topic: challenge for machinists on this board

[dusterdude]

see if you can design a good single carb intake for the 750 engine utiilzing a stock frame.let us know what you come up with.

[MRieck]

Mark
 Keeping in mind the word "good"...it would be tough to do. Intake tract overall length and length differences are a couple of problems. Good fuel distribution is another. I'd think there would be problems with fuel puddles etc. I'd like to see an FI set up myself. It would be expensive, I don't know where you would put the ECU and I don't think the electrical system has enough juice to power it BUT it would be cool.

[volthause]

What carb would you use? I'm trying to think of a single throat, side draft carb with the capacity to feed an inline 4, and nothing is coming to mind.

I think MRieck is spot on about the intake length mis-match that would occur... I also would love to see an injected SOHC.

It should be easy enough to do. Anyone ever messed around with MegaSquirt?

DIY programable fuel injection!

[byidesign]

    Toolmaker Yes, however,
 What if you don't own , the bike in Question.
   Would need Dimensions of Carb spacing{throat to throat x 4 }
     diameter of intakes
       dimensions  of envelope space for {carb/air cleaner}to
        frame clearance, and how much cfm engine
            is bored/ modified, to accept......
         Then maybe a chance at it...........
             
                   Bruce

[Jerry Rxman Griffin aka MuthaF'er]

Yeah, something that would use a carb something along the lines of say a 650 Holley 4 barrel !!

Mike had mentioned Fuel injection. What about the Hilborn injection system that some TQ race guys use? Not  very expensive either.

[GroovieGhoulie]

Why would one want a single carburetor?  What's wrong with one carb per cylinder?

[KilgoreTrout]

Why would one want a single carburetor?  What's wrong with one carb per cylinder?

3 too many to rebuild?

[eldar]

Now I dont know if this would work and I am not entirely sure about the length issue as most cars that ran carbs had different lengths to their cylinders, BUT what if you made the intakes going to the outer cylinders a smaller diameter than the inner cylinders? If we are talking about how fast fuel gets to the combustion chamber, the mix would flow faster in the smaller intakes. If the mix flows faster, it will create a greater vacuum to pull the mix and should then, theoretically, even out if the right diameter for the length could be found.

[Lumbee]

...a single carb design sold on Ebay a few weeks back..single minifold with the carb mounted from the side.  Someone on the Hondachop board said they had ran it in the past.  Said it ran OK at WOT, but not so good for regular riding.  As others have mentioned, I think the physics of a single carb feeding 4 cylinders is just not doable.  Dual carbs is your best bet...Ken over at cycle exchange seems to have that design worked out...

http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm

[Jerry Rxman Griffin aka MuthaF'er]

Why would one want a single carburetor?  What's wrong with one carb per cylinder?

Oh, the sound of that 4 barrel kicking in !!!

[KilgoreTrout]

...a single carb design sold on Ebay a few weeks back..single minifold with the carb mounted from the side.  Someone on the Hondachop board said they had ran it in the past.  Said it ran OK at WOT, but not so good for regular riding.  As others have mentioned, I think the physics of a single carb feeding 4 cylinders is just not doable.  Dual carbs is your best bet...Ken over at cycle exchange seems to have that design worked out...

http://www.cyclexchange.net/Carb%20System%20Comp%20Page.htm

I have buddy with this setup on his chopper. He say's he'll never go back to 4 carbs.

[volthause]

Yeah, something that would use a carb something along the lines of say a 650 Holley 4 barrel !!

right, but that presents a bit of a flow problem. you want to try to avoid using a down draft carb that feeds a horizontal port, and vice-versa.

an added problem is that in order to get enough clearance above the carb, the mounting of the carb would be much lower than the ports. trying to fuel something 'uphill' seems like a bad plan.

[VitaminCB550]

I have a 1963 Morris Minor that has a 4cylinder engine (austin made the motor)... One carb! 35 odd horsepower, but it can be done.

[crazypj]

I was a precision machinist for several years and dont think of this as a challenge, more a waste of time. Why is anyone even discussing it? If you want one carb, buy a Harley or any of the clones from US or Japan. If you want better fuel economy, buy a chinese 125cc single cyl knock off of Honda and get 100+mpg or even better, get C50 copy with almost 200MPG
PJ

[eldar]

Well I doubt a person is looking to do this for economy or something practical. Some just like to tinker or just want somehting different. Personally, I would like the injection instead of a carb. But that is what motorcycling is all about. Doing your thing with your bike. You cant do it to make others happy. Besides it is the spirit of innovation that is what allows technology to go forward. If Mr. Honda didnt have his ideas(whick I am sure others thought were terrible) bikes like our and ones that sprang from them, would not exist.

This is just like the removing the battery ideas people have had. No matter what a person wants to try on their bike, I support it. Sure I think some things are bad ideas, but you never know, someone may just find a new way that does work.

It is all part of keeping our bikes alive and what is more important than that?

[crazypj]

Well I doubt a person is looking to do this for economy or something practical. Some just like to tinker or just want somehting different. Personally, I would like the injection instead of a carb. But that is what motorcycling is all about. Doing your thing with your bike. You cant do it to make others happy. Besides it is the spirit of innovation that is what allows technology to go forward. If Mr. Honda didnt have his ideas(whick I am sure others thought were terrible) bikes like our and ones that sprang from them, would not exist.

This is just like the removing the battery ideas people have had. No matter what a person wants to try on their bike, I support it. Sure I think some things are bad ideas, but you never know, someone may just find a new way that does work.

It is all part of keeping our bikes alive and what is more important than that?

I agree,
 but, if you want to do it, do it,
then show everyone what you did so we can see how cool it is.
PJ

[dusterdude]

i dont think the actual design of it would be rocket science.i am not a machinist or a design type of guy,its an idea to see what might be feasable.as far as carb choice you only need something that will feed 184 cc`s worth of engine capacity at any one time,so i would think a small mikuni or something of that ilk would work just fine.

[eldar]

I would agree with showing people what you did and how. I myself have not seen fit at this time to heavily modify anything. While things like this interest me, I only have 1 bike and would prefer to ride it than have it sit in pieces. If I get a parts bike, well then, let the mods begin!

[ProTeal55]

S&S Super E carb would be a good choice to bolt up to this "experimental" intake.
I would love to go from 4 carbs to 1...

[cb(r)]

Well I doubt a person is looking to do this for economy or something practical. Some just like to tinker or just want somehting different. Personally, I would like the injection instead of a carb. But that is what motorcycling is all about. Doing your thing with your bike. You cant do it to make others happy. Besides it is the spirit of innovation that is what allows technology to go forward. If Mr. Honda didnt have his ideas(whick I am sure others thought were terrible) bikes like our and ones that sprang from them, would not exist.

This is just like the removing the battery ideas people have had. No matter what a person wants to try on their bike, I support it. Sure I think some things are bad ideas, but you never know, someone may just find a new way that does work.

It is all part of keeping our bikes alive and what is more important than that?

Ill drink to that.  I am sure duster would to.  he would drink to most anything.
I have put a little thought into the single carb thing.  I like the dual  looks better but the single can be done it is just the amount of time and money you have to prototype something like this.  time is the essence but money is the resistance with most of us who like to tinker with stuff.  I would like to see a turbo 550 before a single carb 550.  anyone? anyone?

[eldar]

Well I dont know about a 550 but a 750 with an 836 dropped in pushing some boost, well I could get onto that!

[cb(r)]

Well I dont know about a 550 but a 750 with an 836 dropped in pushing some boost, well I could get onto that!

ya that would also tweak the nards.

[dusterdude]

yea,super e is kinda what i had in mind.i have a parts bike/motor i could at least take pics of.only prob right now is im in the middle of rebuilding my house and wont likely get done until this fall.it is something i would seriously like to look into tho.

[etn4runner]

  I would like to see a turbo 550 before a single carb 550.  anyone? anyone?

X2. a turbo 550 would be sweet!

[Green550F]

Allways wanted to make my own FI 

My thought is that it should be a carb replacement Built in electronics with connections for power, timing, and O2, while TPS and MAP should be onboard also. Pre-programed for the displacement to feed. Nice "bolt-on" application.

And when I finish it, I'll share the millions I make on it with everyone here!